I might be an idiot.

So working on my first build and I went a little ebay crazy. I picked up a nice 21" 40 spoke, and then came across an old school springer I couldnt pass up. Once I got them both I realized that the wheel may be too wide for the legs. For sure the hubs are, buuuuuut I was just going to swap them out for a killer spoolie or maybe an old hallcraft if I can find one. Anyways my rim meausures out to : 3" and my rear legs are 3 5/8. I was planning on running a set of avon speedmasters if that makes a difference. Thanks

I am an idiot! I didnt even ask the question.... So is it too wide?

You might squeak by but it's gonna be close. It would be easier to find a narrower rim and avoid the possible hassles.

Pictures might help. a 3.00 X 21 rim is pretty wide, they're usually like 1.60 X 21 for a narrow rim/ 3.00 X 21 Avon.

the size on the rear legs may be hard to see but they measure out to 3 5/8" and the rim measures out to 3" from shoulder to shoulder

Run it because everyone seems to think that a big gap between the fork a wheel is stylish.

Took it to the shop thats helpin' me out with some fab work. We measured a bunch of different brands of mounted tires on the same size wheels. Looks like its gonna work. Thanks for the input

Run a avon sppedmaster on there! It will fit fine and trust me they look soo sick on a 3" wheel... I'll see if i can find a pic on a 3" wheel.